Stationary Jams - Canon imageCLASS MF4890dw Service Manual

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Technical Overview > Pickup And Feeding System > Reversal Delay Jam > Stationary Jams

■ Stationary Jams

● Pickup Stationary Jam
Without pre-feed, a feed stationary jam is determined if the TOP sensor (PS751) cannot
detect the trailing edge of paper within 3960 (7920) ms after the leading edge is detected by
the TOP sensor (PS751).
With pre-feed, a feed stationary jam is determined if the TOP sensor (PS751) cannot detect
the trailing edge of paper within 4740 (9480) ms after the leading edge is detected by the
TOP sensor (PS751).
Note :
"4740 ms" is the time equivalent of two LGL sheets. If LGL sheets are fed after A4-size
standard continuous printing at pre-feed, the second LGL sheet may be fed as an A4-
size standard sheet and therefore two LGL sheets may be fed almost with no break. To
prevent this from stopping the machine by a jam, the feed stationary jam detection time
during pre-feed is set to 4740 ms at full speed.
● Delivery Stationary Jam
The delivery sensor (PS701) is monitored for 265 (530) ms from 715 (1430) ms after no-
paper detection by the TOP sensor (PS751), a delivery stationary jam is determined.
Note :
The margin is set to 20 mm because paper may spring up.
● Reversal Stationary Jam
After the start of reversal, if the delivery sensor (PS701) does not detect the no-paper status
within 2570 (5140) ms after paper detection, a reverse stationary jam is determined.
Note :
This jam is determined if the delivery sensor (PS701) keeps detecting sensor for the
time of delivering LEGAL + 30 mm.
2 Technical Overview > Pickup And Feeding System > Reversal Delay Jam > Stationary Jams
● Pickup Stationary Jam during auto delivery
A pickup stationary jam is determined if the Paper Lead Edge Sensor (PS751) detects
presence of paper at the time of 1115 msec elapsed after the start of auto delivery and then
the Paper Lead Edge Sensor (PS751) detects presence of paper after the paper continued to
be fed for 2730 msec.
● Delivery Stationary Jam during auto delivery
If there is no paper at the TOP sensor (PS751) 1235 (2470) ms after the start of auto delivery
and there is paper at the delivery sensor (PS701) after further paper delivery of 980 (1965)
ms, a delivery stationary jam is determined.
If there is paper at the TOP sensor (PS751) 1235 (2470) ms after the start of auto delivery
and there is paper at the delivery sensor (PS701) after further paper delivery of 3075 (7410)
ms, a delivery stationary jam is determined.
● Delivery Stationary Jam during cleaning
A delivery stationary jam is determined if the Fixing Delivery Sensor (PS701) fails to detect
absence of paper within 2535 msec since the Main Motor started rotating after the cleaning
step.
● Delivery Stationary Jam during warm-up rotation
If the delivery sensor (PS701) detects paper during warm-up rotation, a delivery stationary
jam is determined.
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